The invention relates to a display element capable of being mounted on a printed circuit board. Such display elements allow to display certain information provided by the illumination of light sources like LED""s in an area or plane in front of or adjacent to the printed circuit board by guiding the light from the light source to the display area.
European Patent EP 0 421 824 B1 discloses a display element which serves to be fitted on printed circuit boards using SMD technology and comprises a housing having a T-shaped opening. In this case, the T-shaped opening accommodates an LED (light-emitting diode) at the end facing the printed circuit board, while another end accommodates a lens which projects from the housing and, opposite from the LED, has a slanted face adjacent to which a plastics composition is filled into the T-shaped opening from the third end thereof. This forms an inner area which reflects incident light from the LED to the exit end of the lens. In this case, the LED forms the base of the display element and serves for fixing the latter on a printed circuit board. A display element of this type has a relatively complicated structure, especially as it comprises three individual parts and the plastics composition which have to be assembled to form the display element.
It is an object of the invention to provide a display element which can be produced in a substantially simplified manner.
Thus, the invention concerns a display element capable of being mounted on a printed circuit board, comprising:
at least one LED provided with connecting wires;
a device for illuminating a light exit area extending substantially perpendicularly to the direction of light propagation;
an optical waveguide forming said illuminating device and the light exit area;
wherein said optical waveguide has a recess, which has a light coupling-in area for light from the at least one LED and in which the at least one LED is fixed;
said optical waveguide having at least one supporting element for support on a printed circuit board;
wherein the connecting wires of the at least one LED have feet which preferably can be soldered onto the printed circuit board by means of SMD technology.
By virtue of the fact that the display element used is an optical waveguide which accommodates the LED and forms the light exit area, and thus the display area, only two structural parts that are simple to connect to one another are required for the display element, and a separate housing as in the case of EP 0 421 824 B1 into which different parts can be inserted and a plastics composition can be introduced is not required. This considerably simplifies production, to be precise irrespective of the type of LED used or of the desired fitting on a printed circuit board, i.e. technologies other than the SMD technology can also be used.
Further objects, advantages and embodiments of the invention will become apparent from the following description and from the claims.